Howdy.
Windows Live Writer doesn't always detect or refresh the themes correctly, but you might want to try a free utility to try to adjust or FIX the theme in Windows Live Writer.
The utility can be found here:
http://blogs.msdn.com/brandonturner/archive/2009/08/16/broken-theme-in-windows-live-writer-you-can-fix-it.aspx
Read through the instructions, you use it correctly and you just might not have an issue soon.
Hope this helps.
Thanks,
L. Henry Jr.
http://www.lehsys.com
Sadly I've tried everything on that post and I'm still getting the unhandled exceptions. The folder's there, the css and the images too... just not the HTML. Any ideas?